UN warns of worst mass extinctions for 65m years

Humans have provoked the worst spate of extinctions since the dinosaurs were wiped out 65m years ago, according to a UN report that calls for unprecedented worldwide efforts to address the slide.

The report paints a grim picture of life on earth, with declining numbers of plants, animals, insects and birds across the globe, and warns that the current extinction rate is up to 1,000 times faster than in the past. Some 844 animals and plants are known to have disappeared in the last 500 years.

Released yesterday to mark the start of a UN environment programme meeting in Curitiba, Brazil, the report says: "In effect, we are currently responsible for the sixth major extinction event in the history of earth." A rising human population of 6.5bn is wrecking the environment for thousands of other species, it adds, and undermining efforts agreed at a 2002 UN summit in Johannesburg to slow the rate of decline by 2010. The global demand for biological resources now exceeds the planet's capacity to renew them by 20%.

The report, Global Biodiversity Outlook 2 from the secretariat of the UN Convention on Biological Diversity, says: "The direct causes of biodiversity loss - habitat change, over-exploitation, the introduction of invasive alien species, nutrient loading and climate change - show no sign of abating." It is bleaker than a first UN review of the diversity of life, issued in 2001, and says the 2010 goal can only be attained with "unprecedented additional efforts".

About 6m hectares (15m acres) of primary forest are felled each year and about a third of mangrove swamps have been lost since the 1980s. In the Caribbean, average hard coral cover has declined from 50% to 10% in the last three decades. Up to 52% of higher bird species studied are threatened with extinction and the number of large fish in the North Atlantic has declined by two-thirds in the last 50 years.

The report concludes: "Biodiversity is in decline at all levels and geographical scales," and international travel, trade and tourism are expected to introduce more alien species to fragile ecosystems.

On the positive side, the number and size of protected areas is increasing, though most types of natural environment fall short of the target to protect 10%. About 12% of the land surface is protected, against 0.6% of the oceans.